So I was talking to this engine builder/racer the other day when the topic of my 455 build was brought up.

He asked what cam I'd be using, and I said "a hydraulic roller set-up."

He then asked, "why not a solid roller?"

I honestly never even thought of running a solid roller, so I didn't really know how to respond.

So my question is, should I look into a solid roller cam for this engine?

Like I said, I have never really thought of going that route.

Thanks.

 

What's the application? Anticipated rpm range? desired HP?

 

What is the rest of the combo? Heads, intake, trans, rears, etc?

 

Aggressive solid roller profiles take a lot of spring pressure and are hard on parts. I wouldn't use one for a street application where you don't need that last little bit of power. The reason for hydraulic rollers with modest spring pressures is largely reduced friction, because of the emissions-formula engine oils today.

 

Application: 1964 Olds Cutlass 2-door Post with full interior. Used on the street and the quarter mile.

Assembled Shortblock:
455 Bored +.030 with 25cc dished ICON pistons;
Stock Rods with ARP bolts;
ARP Studs on the Mains.

Anticipated RPM range: 1,300-6,000.

Desired HP: 475.

I also want the car to have REALLY snappy and crisp throttle response throughout the RPM range. Especially on the lower end. Like, I want to barely touch the gas pedal to make the car move. Like a hairpin trigger.

Heads: Pro Comp.

Intake: Dual Plane.

Trans: TH350.

Gears: 3.73 (not sure how tall the tires are, but that's changing anyway because I'm buying slicks).

I do want every last bit of power. I am not sure what you mean by they are "hard on parts." And I figure the roller bearing on the roller lifters would make the issue of today's oils irrelevant. Besides, there's race oil available with all the good stuff still available.

 

I think what he means "Hard on parts" is since the forces required to open the valves and keep them open are greater it puts undo strain on the valve train over time. Okay for 1/4 mile at a time but not for miles at a time maybe. I could be wrong.

 

With you current combo you're at about 9.5:1, hardly solid roller territory.

As mentioned solid roller cams typically have very fast ramps that require the spring pressures mentioned. Certainly overkill for your application at this point imo.

I'd raise the compression to 10.0:1 or better then use a hyd roller in the mid 230@.050 range. Get one with greater lift to better utilize those heads.

Let me know if I can help.
Thanks

 

I was planning on contacting you once I figuered out which route to take.
So I should shoot for 10:1?
I guess I could get the thinnest head gaskets possible or mill the heads, although I'm not sure if those methods would be sufficient to make 10:1.

You said to go with a hydraulic roller after 10:1, but what about at 9.5:1? Should I still go with a hydraulic roller?

I'm sort of bummed about not being able to run a solid roller. I wanted to try one just for the experience. I had a flat tappet hydraulic in my Olds 350. I have a hydraulic roller in my daily driver Dodge Magnum V8, but have yet to try a solid lifter valvetrain.

 

IMO I'd shoot for 10.0:1 no matter what.
If you want to go solid roller do so. It's a bit overkill for your application but if you want to do it then go for it.

 

There are solid roller profiles from moderate to extreme in aggressiveness of the lift profiles, requiring from moderate to extreme spring pressures. They are also available in lifts and durations for whatever purpose you have, within reason. Don't be bummed, no one is denying you the excitement of a solid roller cam. It is just a lot of hassle unless you want the car to run 10s or better in the quarter mile. Lots have run 10s with flat tappets, using good oil as you noted.

 

Thanks for all the responses and happy Thanksgiving.